Reduction of sulfate found in barite (BaSO4), sodium sulfate (Na2SO4) and phosphogypsum (CaSO4• xH2O) and the significance of sulfide production in the sequester of selected heavy metals and trace elements were studied. Suspensions of Mississippi River alluvial sediment were equilibrated under controlled redox (‐250 mV) conditions. Sodium sulfate and phosphogypsum additions resulted in a large increase in sulfide levels in the sediment suspensions. Water soluble barium (Ba), cadmium (Cd), iron (Fe), and manganese (Mn) concentrations decreased significantly when sodium sulfate and phosphogypsum were the sulfate sources. Solubility of heavy metals and trace elements was substantially affected. Barite addition did not significantly affect the concentrations of water soluble sulfate and sulfide formation. This was attributed to the low solubility of barite as compared to the two other sulfate sources.